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Alaska Section, AWRA, Northern-Region Brown-Bag Meetings
January 26, 2018 Tundra Be Dammed: Beaver Colonization of the Arctic Dr. Ken Tape, Research Assistant Professor, Increasing air temperatures are changing the arctic tundra biome. Permafrost is thawing, snow duration is decreasing, shrub vegetation is proliferating, and boreal wildlife is encroaching. Here we present evidence of the recent range expansion of North American beaver (Castor canadensis) into the Arctic, and consider how this ecosystem engineer might reshape the landscape, biodiversity, and ecosystem processes. We developed a remote sensing approach that maps formation and disappearance of ponds associated with beaver activity. Since 1999, 56 new beaver pond complexes were identified, while only 4 beaver ponds exhibited drying, indicating that beavers are colonizing a predominantly tundra region (18,293 km2) of northwest Alaska. We discuss rates and likely routes of tundra beaver colonization, as well as effects on permafrost, stream ice regimes, and freshwater and riparian habitat. Beaver ponds and associated hydrologic changes are thawing permafrost. Pond formation increases winter water temperatures in the pond and downstream, likely creating new and more varied aquatic habitat, but specific biological impacts are unknown. Beavers create dynamic wetlands and are agents of disturbance that may enhance ecosystem responses to warming in the Arctic. Select Presentation Figures Figure A. Tundra landscape in the western Brooks Range. When do YOU think beavers arrived?, High Resolution Image Webex Registration Available
Some Additional References of Interest by Dr. Ken Tape
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